"CALCIUM NEED AND CALCIUM UTILIZATION"

To the Editor:  —My purpose was to stress the fact that "the existence of optimum conditions in regard to calcium cannot be taken for granted, but that special effort is necessary to assure adequate supply and utilization of this element." There was no intention, as implied by the correspondent, to ascribe to calcium the chief rôle in the maintenance of health or in the prolongation of life.Calcium, of course, is necessary to life, but so admittedly are numerous other elements and substances. Not one of these plays its rôle alone. True evaluation of function, so far as it is possible, comes only after study of the various factors, both separately and in their interrelationships. It is never a simple problem.Dr. Baron's observation that "conclusions based on the realms of probability are questionable" is undeniably true. The conclusions in question, however, are based on acceptable evidence, despite the word